System for locking filler caps

ABSTRACT

A system for locking caps, to be used especially in those tanks containing inflammable liquids, said cap (10) comprising a body (11) which is seated over a tank nozzle (2), an articulating lock arm (14) bearing a respective lock displaceable between locking and releasing positions relative to the tank nozzle upon the corresponding angular movement of the lock arm, an arm activating assembly provided in the cap body (11) and whereto a drive shaft (51) is mounted in a freely rotating manner and to which torque is selectively applied, an impelling piston (15) coupled to lock arm (14) and being axially displaced between corresponding locking and releasing positions of the lock arm (14); an electromagnetic clutch causing the selective axial displacement of the impelling piston (15) between operational limit positions upon the rotation of the drive shaft (51) and comprising a coupling means displaceable between engaging and disengaging position; coil means (60) causing the displacement of the coupling means to the engaging position, an electronic switch (40) provided with a primary transformer (L1) coupled to a secondary transformer (L2) mounted on the cap body (11) and including in the secondary transformer enough current to operatively energize the coil means (60). A SYSTEM FOR LOCKING FILLER CAPS

FIELD OF THE INVENTION

The present invention refers to a lock system for the filling caps ofclosed tanks, especially those tanks containing inflammable liquids suchas the fuel tanks of service (gas) stations.

BACKGROUND OF THE INVENTION

Fuel supply to service stations takes place upon the arrival of thetransporting tanker truck, when each tank of said service stations isopened.

The filling is achieved by removing the filling cap at the feedingnozzle of the fuel tank, which opens toward the surface of the servicestation and through which a suitable conducting element, such as a hose,is introduced, providing a temporary fluid communication between thereservoir of the tanker truck and the tank of the service station. Theremoval of the filling cap is achieved by the easy opening of aconventional padlock, which hinders the movement of the cap lock armsand retains the cap against the nozzle of the tank.

Due to the easy access to the inside of the service station tanks,resulting from the precarious closing system thereof, the contents ofsaid reservoirs are liable to composition adulterations, suchadulterations being difficult to prove.

One solution for this problem is to provide the tank filling caps withclosing and locking systems which are electrically activated at welldetermined time periods. Nevertheless, said solution cannot be appliedto fuel tanks, due to the danger of explosion caused by electricalsparks, which may occur in this type of lock systems.

Moreover, even though the electrically activated systems present themost elaborate closures in the state of the art, they are still easilyactivated by conventional electric connectors, which leave no trace ofhaving had the tank cap removed at times which are not solely for thepurpose of supplying the tank.

DISCLOSURE OF THE INVENTION

Thus, it is an object of the present invention to provide a lock systemfor the filling caps of closed tanks which can deny access to the insideof said tanks between supply periods of time.

Another object of the present invention is to provide a lock system suchas that cited above, which does not pose risks, as for exampleexplosions, to those environments in which said reservoirs to be lockedare located.

These and other objectives are reached through a lock system for thefilling caps of closed tanks, especially those tanks containinginflammable liquids, said cap comprising: a body seated over therespective tank nozzle and articulating at least one lock arm, bearing arespective lock which can be displaced between the locking and releasingpositions in relation to the nozzle, when there is a correspondingangular movement of the lock arm, said system further comprising an armactivating assembly provided in the cap body and including a driveshaft, mounted axially on the cap body in a freely rotating manner andhaving an end which is accessible on the outside of the cap and to whicha torque tool is selectively applied; at least one impelling piston,mounted axially through the cap body, so that one outer end may becoupled to the lock arm and the opposite inner end to the filling cap,each impelling piston being axially displaced between a first positioncorresponding to the lock arm locking position and a second positioncorresponding to the lock arm releasing position; at least oneelectromagnetic clutch, mounted to the cap body, so as to cause theselective axial displacement of the impelling piston between the firstand second operational limit positions thereof when the drive shaftrotates, said clutch comprising a coupling means, which is displacedbetween an engaging position, in which the rotation of the drive shaftcauses the axial displacement of the impelling piston and a disengagingposition, in which the drive shaft rotates freely upon torqueapplication; at least one coil means coupled to the cap body, so as tocause, when energized, the displacement of the coupling means toward theengaging position; an electronic switch provided with a transformerprimary (L1) energized at low power and coupled to a transformersecondary (L2) mounted on the cap body, so as to induce in thetransformer secondary (L2) enough current to operationally energize thecoil means of the electromagnetic clutch.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described below, based on the attached drawings,in which:

FIG. 1 schematically illustrates a filling cap according to the presentinvention, which is mounted onto the tank nozzle in the closed capposition and in the open cap position (dashed lines);

FIG. 2 schematically illustrates the cap of FIG. 1 in an open state andprovided with the lock system of the present invention;

FIG. 3 is a schematic top plan view of the filling cap of the presentinvention;

FIG. 4 schematically illustrates a lock pin provided in the cap body;

FIG. 5 is a block diagram of the closure system of the presentinvention;

FIG. 6 illustrates an electronic circuit associated to the block diagramof FIG. 5 and provided in the filling cap; and

FIG. 7 illustrates an electronic circuit associated to the block diagramof FIG. 5 and provided with an electronic switch.

BEST MODE FOR CARRYING OUT THE INVENTION

According to the figures presented, the lock system of the presentinvention comprises a filling cap 10 for the closure of a feed nozzle20, which is disposed at an upper wall portion of a tank (notillustrated) and which is constructed under the surface of a servicestation. Said feed nozzle 20 presents an access end 20a facing saidsurface and an opposite end (not illustrated), facing the inside of thereservoir. The access end 20a is in the form of a body, which projectsfrom a recessed portion of said surface and which is concentric to saidnozzle, the profile of which being defined so as to receive and retainthe filling cap 10. The height of the projecting portion of said accessend 20a over the lower surface of said recess is such that, in the tankclosed position, the filling cap 10 is substantially coplanar with thesurface of the service station.

The filling cap 10 is "T" shaped, having a cap body 11 of the closed andsubstantially cylindrical type and bearing, at one end, a head portion12, from which peripheral edge there is downwardly projected aperipheral skirt 13 whereto there is mounted, in a suitable manner, suchas by tempered pins P, at least one, but preferably a pair of lock arms14, which are diametrically opposite to each other and mounted to theperipheral skirt 13, by means of the respective articulated end 14a. Theopposite end 14b of each of said lock arms 14 is mounted to acorresponding impelling piston 15 of an arm activating assembly, whichis axially displaced through the inside of the cap body 11 between afirst position corresponding to the lock arm locking position andachieved by the engagement of a locking portion of each lock arm 14 tothe tank feed nozzle, and a second position corresponding to the lockarm releasing position. In the preferred construction, lock arms 14 mayalso be in a partially open state. The assembly of the opposite end 14bof each lock arm 14 to the respective impelling piston 15 takes place bythe sliding fit of a guide pin 16, which is provided at a free end 15aof each said impelling piston 15 and which projects from a side wall ofsaid piston, orthogonally to the axis thereof. Said guide pin 16 isengaged in a lateral slot 14c, preferably a through slot, which isaxially defined at the opposite end 14b of each said lock arm 14 andthrough which each said guide pin 16 slides when there is an opening ora closing movement of filling cap 10.

In the illustrated construction, the cap body 11 is closed at one of theends thereof, by a bottom cap 17 supporting in its face internal to saidcap body 11 a supporting base 18 of the lock system of the presentinvention, to be described later.

When in the locking position, an engaging portion 14d at the articulatedend 14a of each lock arm 14 fits into a restricted annular region 21 ofthe projecting end of the feed nozzle 20, until the opening of thefilling cap 10 has been commanded, when the movement of each impellingpiston 15 withdraws said engaging portions 14d, unlocking said fillingcap 10 from the feed nozzle 20.

Each impelling piston 15 further presents an opposite end 15b, which isinternal to the cap body 11 and which is affixed by a pinion 30internally screwed on and which acts in the opening and closingmovements of the filling cap 10.

According to the present invention, the arm activating assembly furtherincludes, mounted on the inside of cap body 11, an electromagneticclutch which, when activated by an electronic activating switch 40mounted on a tanker truck, not illustrated, causes the selective axialdisplacement of the impelling piston 15, between the first and secondoperational positions thereof and allows for the opening and closing ofsaid filling cap 10. The electronic switch 40 is powered by the tankertank battery by means of suitable cables C and connected to the fillingcap 10 in an engaging portion 10a thereof and upon the opening of saidfilling cap 10 is maintained in this state of connection until theclosure of said filling cap 10 has been effected. The electronic switch40 is programmed, so that after a determined average time interval forthe filling operation has elapsed, it de-energizes the filling cap 10,avoiding the replacement thereof in the reservoir nozzle. In this state,only a technician can reinstate normal use conditions. Said electronicactivating switch 40 comprises a transformer primary L1 energizable atlow power; at least one manual activating button 42, by which theoperator can command the end of the open or closed states of the fillingcap 10 when, for any reason, the electronic switch 40 detects thefilling cap 10 to be in a partially open state; and at least one audiovisual signal 43, which indicates to the operator the end of the openingor closing operations of the filling cap 10, obtained by a command fromthe electronic switch 40 or when its coupling to said filling cap 10 hasnot been accomplished. The electronic activating switch 40 includes atleast one electromagnetic communicating element, preferably a firstoptic transmitter T1 and a first optic receptor R1, which communicaterespectively with a second optic receptor R2 and a second optictransmitter T2 provided in the engaging portion 10a.

The arm activating assembly further comprises a drive shaft 51, which isaxially disposed through the inside of the cap body 11 and concentric tothe filling cap axis, having an end 51a mounted on the supporting base18 and an opposite end 51b engaged, by means of key 52, to an activatingelement 53, which receives on a face external to the filling cap 10 atorque tool, such as a manual crank (not illustrated), by which the userselectively moves said filling cap when it has been released from theaction of the electromagnetic clutch.

The electromagnetic clutch further comprises a coupling meansdisplaceable between an engaging position in which a turn of the driveshaft causes the axial displacement of the impelling piston, and adisengaging position, in which the drive shaft rotates freely when thereis torque application thereon, this coupling means including atransmitting means having an endless means in the form of an endlessscrew tubular element 54, and a pinion 30, which involves the driveshaft 51, so as to enable it to present only rotational movement andwhose external threaded surface permits the axial movement of pinion 30between a cap closed position defined when said pinion 30 is locatednear the supporting base 18, and an open cap position, when said pinion30 is adjacent to the end portion of the cap body 11, opposite to thesupporting base 18. The filling cap 10 of the present invention isprovided in the inner portion of cap body 11 thereof, with at least onefirst and one second position sensors S1, S2, arranged axially removedone from the other in order to sense the presence of pinion 30 in theclosed cap and open cap positions. In the preferred illustratedconstruction, these sensors are electronic sensors of the "Hall" typewhich detect the presence of a corresponding emitter S3 of this system,provided in an external wall portion of pinion 30 and adjacent to saidsensors.

The coupling means further includes adjacent to each end of the driveshaft 51, a respective coil means 60 which, when energized, causes themagnetic coupling between the drive shaft 51 and the endless screwtubular element 54, to permit the axial displacement of pinion 30through the inside of cap body 11, and consequently the movement of lockarms 14 between the open and closed cap positions.

Each coil means 60 comprises a preferably cylindrical tubular sleeve 61,which concentrically involves a respective end portion of drive shaft 51and the adjacent end of the endless screw element 54, and which isspaced from said parts and supported on an appropriate supporting basemounted on the cap body 11.

External to the tubular sleeve 61 there is arranged a coil 62, which isenergized upon the coupling of the switch element 40 to the filling cap10, so as to originate a magnetic field which induces the coupling andretention of tubular sleeve 61 to said coil 62, impeding the rotationalmovement of tubular sleeve 61 in relation to the drive shaft 51, whenthe turning of the latter is caused by the action of the manual crank.

The intensity of the coupling force should be at least sufficient tocause an angular phase displacement between the turn of the drive shaft51 and the eventual sliding of the tubular sleeve 61 by the coil 62,while the clutch is axially displaced between the open and closedfilling cap positions.

The tubular sleeve 61 bears, internally, a helical spring element 63,having one end affixed to said tubular sleeve 61 and the opposite endaffixed to the drive shaft 51, said spring element 63 having asufficient axial length to involve the adjacent end portions of thedrive shaft 51 and endless screw element 54.

The usage of two assemblies of coil means 60 in the preferred solutionis due to having spring torque in only one turning direction. The springdoes not "adhere" in the opposite direction.

When coupling the electronic switch 40 to the filling cap 10, firsttransmitter T1 of the electronic switch 40 informs the second receptorR2 of the filling cap 10 that the coupling between said parts has beenaccomplished and the first optic receptor R1 of said electronic switch40 then receives the information regarding the characteristics andconditions of the coupled filling cap 10 by means of the secondtransmitter T2 thereof. These features will be compared with thecharacteristics and conditions, which are expected for this cap andwhich have been previously informed to a central processing unit(described later on) provided in the electronic switch 40, before saidunit commands the unlocking operation for opening the filling cap 10. Ifall information is in agreement, the electronic switch 40 begins tounlock the electromagnetic lock mechanism, releasing the cap 10 so thatit may be opened manually.

In order to release cap 10 from the electromagnetic lock, the primary L1of transformer 41 in the electronic switch 40 is energized, producing amagnetic field which induces a current in a transformer secondary L2provided in filling cap 10.

This current energizes coil 62, originating a magnetic field whichretains tubular sleeve 61 against the surface of said coil, avoiding therotational movement of said sleeve upon the rotation of the drive shaftof said sleeve upon the rotation of the drive shaft 51. While in thelocking condition, the torque to the drive shaft 51 causes the freerotation of the tubular sleeve 61 through the coupling thereof to saiddrive shaft 51 by the spring element 63.

When the coil 62 retains the tubular sleeve 61, the turning of the driveshaft 51 causes torsion on spring element 63 which, as it decreases thediameter of the coils thereof, conducts the contact and the adhesion ofsaid spring element 63 to the adjacent ends of the drive shaft 51 andendless screw 54, permitting the transfer of rotational movement fromsaid drive shaft 51 to said screw element.

The rotation of the endless screw 54 is then transmitted to pinion 30 asa linear movement, in order to allow the axial displacement thereof andof the impelling pistons 15, in order to open filling cap 10. During theopening movement of filling cap 10, pinion 30 is induced to makecontact, on the front surface thereof, with the first end of a lock pin55 mounted on the inside of cap body 11, the second end being oppositeto the first end and projecting from the cap outer surface, preferablyparallely to the drive shaft 51 of said cap 10 and being fitted into ahousing in the form of a slot provided at a coupling end 40a of theelectronic switch 40, in order to lock said switch to the filling cap 10during the opening movement of the latter, until said filling cap isonce again closed, avoiding a possible changing of the reservoir cap.

Lock pin 55 is surrounded by a return spring 56, which is located in thecap body 11 and which is elastically deformed between a firstcompression condition, achieved when cap 10 is opened, defining amaximum spring compression situation, and a second compressioncondition, achieved when cap 10 is in a closed state, defining a minimumcompression situation.

The maximum or minimum compression conditions are reached respectivelyby pinion 30 getting close to or moving away from the open cap position.

When the clutch reaches the open cap position, electronic switch 40commands coil 62 of the opening coil means to deenergize.

Tubular sleeve 61 is released and the endless screw 54 returns to a freerotation state, avoiding any change in the open state of pinion 30 andconsequently the removal of the electronic switch 40 from the fillingcap 10. These conditions will remain until the closing operation of saidfilling cap 10 has begun.

After the seating of filling cap 10 onto the feed nozzle of thereservoir, the electronic switch 40 is activated and transmitter T1 andreceptor R1 elements communicate with corresponding receptor R2 andtransmitter T2 elements provided in said filling cap 10, verifying theopen state thereof before commanding the energization of coil 62 of thecap closing coil means which, as in the opening operation, causestubular sleeve 61 to brake, permitting the transmission of therotational movement of drive shaft 51 to the endless screw 54 and theconsequent axial movement of pinion 30 from the open condition to theclosed condition of said filling cap 10.

With this movement, lock pin 55 is once again placed in an inoperativecondition, retracted to the inside of cap body 11 and releasing theelectronic switch 40 from the coupling with filling cap 10. When theclosed cap position is reached, the second position sensor S2 informssaid state to electronic switch 40, which commands that coil 62 nolonger be energized, releasing tubular sleeve 61 to rotate freely.

The opening and closing conditions are communicated to the operator bymeans of an audio and/or visual signal of a defined duration.

Electronic switch 40 automatically commands the opening and closing offilling cap 10, when the exchange of information between the twoindicates that said filling cap 10 is in one of the closing or openinglimit positions. If filling cap 10 is in a position between said limitpositions, electronic switch 40 will inform the operator, who willdecide, by manually activating button 43, the operation to be commandedby electronic switch 40. When filling cap 10 is closed, a cap protectingelement 19 is mounted against the engaging portion 16a of said fillingcap 10.

In addition to the information regarding the closure of filling cap 10,the optic communication between said cap and the activating electronicswitch 40 further informs the latter about the identification of thefilling cap 10, the quantity of fuel of the tank on which said cap hasbeen mounted, the date of the last opening thereof, etc.

Electronic switch 40 may be previously programmed to identify a number Nof caps per trip of the tanker truck and to store information obtainedfrom these caps for transmission to an information center.

The transmission of energy and the exchange of information betweenfilling cap 10 and the transportation vehicle, in order to cause thelocking and unlocking of said filling cap 10, uses electronic circuits,which will be described ahead.

Filling cap 10 is provided with an electronic system of energizationincluding a cap feed circuit 100, presenting the transformer secondaryL2 and a first outlet 100a, sending electric current, resulting from theenergization of said secondary L2, to a first microprocessor circuit110, provided in filling cap 10, by means of a first inlet 110a thereof.

The first microprocessor circuit 110 further presents a second and athird inlet 110b, 110c, communicating information from the positiondetecting circuit 120, which informs the first microprocessor circuit110 of the open state of filling cap 10.

The transformer of the electronic switch 40 is preferably a highfrequency oscillator of a power oscillating circuit 200 of saidelectronic switch 40 and which presents a first inlet 200a communicatingsaid oscillating circuit 200 with a second microprocessor circuit 210provided in said electronic switch 40, which receives information tocommand the opening or closing of filling cap 10, when opticcommunication between the latter and said electronic switch 40identifies said cap as being correct and whether it is in a closed oropen state.

The first microprocessor circuit 110 presents as well a fourth inlet110d to receive information from the first optic transmitter T1 of theelectronic activating switch 40 through the second optic receptor R2provided in the filling cap 10 and electrically connected to the feedcircuit 100 thereof and which commands the start up of the cap openingand closing operations. The second transmitter T2 of the filling cap 10communicates to the first optic receptor R1 of the electronic switch 40the identification data from filling cap 10, when electronic switch 40engages filling cap 10, and the data referring to the end of theoperations commanded by said activating switch 40. These data are sentto the second optic transmitter T2 of filling cap 10 by a first outlet110e of the first microprocessor circuit 110 thereof which furtherpresents second and third outlets 110f, 110g communicating respectivelywith inlet 130a of a protecting activating element 130 of the capopening clutch assembly 140 and an inlet 150a of a protecting activatingelement 150 of the cap closing clutch assembly 160.

The communication of each protecting activating element 130, 150 to therespective clutch assembly 140, 160 is made by connecting eachcorresponding inlet 140a, 160a of said activating elements with therespective outlets: 130b, 150b of said protecting activating elements130, 150.

The first microprocessor circuit 210 of electronic switch 40 presents afirst inlet 210a receiving signal from the outlet 220a of a tensionregulating circuit 220; a second inlet 210b, receiving information fromfilling cap 10, by means of first optic receptor R2 of electronic switch40; a third inlet 210c receiving instructions from activating button 43;a first outlet 210d in communication with first inlet 200a of the poweroscillating circuit 200; a second outlet 210e carrying instructions tofirst optic transmitter T1 of electronic switch 40 to be sent to theelectronic circuit of the filling cap 10; a pair of third outlets 210f,activating the visual device 43 which informs about the opening orclosing conditions of the filling cap and a fourth outlet 210g foractivating the sound alarm device 43.

The electronic switch 40 also includes a timer which automaticallyinterrupts the supply of energy to the oscillator if the operations tobe achieved do not occur within the average time interval, which hasbeen determined and informed to the second microprocessor 210 circuit ofthe electronic switch 40, preventing the system from being inadvertentlyleft on.

We claim:
 1. A system for locking filler caps, to be used especially intanks containing inflammable liquids, said cap (10) comprising a body(11) which is seated over a respective tank nozzle (20) and articulatingat least one lock arm (14) bearing a respective lock which can bedisplaced between locking and releasing positions relative to thenozzle, when there is a corresponding angular movement of the lock arm,wherein it comprises an arm activating assembly provided in the cap body(11) and including a drive shaft (51) mounted axially in the cap body(11) in a freely rotating manner and having one end (51b) accessiblefrom the outside of the cap and to which a turning tool is attachable;at least one impelling piston (15) mounted axially through the cap body(11) so that it will have an external end (15a) coupled to the lock arm(14) and an internal end (15b) inside the filling cap (10), each of saidimpelling pistons (15) being axially displaceable between a firstoperational limit position corresponding to the lock arm lockingposition and a second operational limit position corresponding to thelock arm releasing position;at least one electromagnetic clutch mountedin the cap body (11) so as to cause the selective axial displacement ofthe impelling piston (15) between the first and second operational limitpositions upon the rotation of the drive shaft (51), said clutchcomprising a coupling means, displaceable between an engaging position,in which the rotation of the drive shaft (51) causes the axialdisplacement of the impelling piston (15) and a disengaging position, inwhich the drive shaft rotates freely upon torque application; at leastone coil means (60) coupled to the cap body (11) so as to cause, whenenergized, the displacement of the coupling means to the engagingposition; an electronic switch (40) provided with transformer primary(L1) energized at low power and coupled to a transformer secondary (L2)mounted in the cap body (11), in order to induce in the transformersecondary (L2) enough current to operatively energize the coil means(62) of the electromagnetic clutch.
 2. The system according to claim 1,wherein it comprises a movement transmitting means, constantly coupledto one of the parts defined by the impelling piston (15) and the driveshaft (51) and being selectively coupled to the other of said partsthrough the coupling means, so as to cause the axial displacement of theimpelling piston (15) when the coupling means is displaced toward theengaging position thereof.
 3. The system according to claim 2, whereinthe movement transmitting means includes a pinion (30) and an endlessscrew (54) being at least one of said parts of the pinion (30) and theendless screw (54) constantly engaged to one of said parts defined bythe impelling piston (15) and the drive shaft (51), the coupling meansdefining the connection mechanism between two adjacent parts of saidpiston-pinion-drive shaft parts.
 4. The system according to claim 3,wherein the endless screw (54) and the drive shaft (51) are coaxial, thecoupling means being defined by a helical spring element (63), which isdisposed around the adjacent portions of the drive shaft (51) and theendless screw (54) and which has an end affixed to the drive shaft (51)and the other end to a tubular sleeve (61), which rotates together withthe drive shaft (51) when the coil means (60) is de-energized and whichis magnetically braked by the coil means (60), upon the energization ofthe latter, so as to make the helical spring (63) press said adjacentportions of the drive shaft (51) and the endless screw (54),consequently restricting the mutual rotation thereof.
 5. The systemaccording to claim 4, wherein the endless screw (54) is an externallyscrewed tubular element involving part of the drive shaft (51).
 6. Thesystem according to claim 5, wherein the internal end (15b) of thepiston carries the pinion (30).
 7. The system according to claim 6,wherein the pinion (30) activates, during the displacement thereoftoward a second limit position, a lock pin (55) mounted in the cap body(11), so that a first end thereof reaches the electronic switch (40),engaging the latter to the filling cap (10) until the pinion (30)returns to its first limit position.
 8. The system according to claim 7,wherein open and closed positions of the cap are detected by positionsensing elements (S1, S2) disposed in the cap body (1I).
 9. The systemaccording to claim 8, wherein the pinion (30) further includes anotherposition sensing element (S3) communicating with the position sensingelements (S1, S2) of the cap body (11).
 10. The system according toclaim 1, wherein the electronic switch (40) includes a firstmicroprocessor circuit (210) commanding the energization of thetransformer primary (L1) when informed of the filling cap operationalcondition by information transmitting elements (T1, T2) and receivingelements (R1, R2) provided in the respective coupling portions (10a,40a) of the filling cap (10) and electronic switch (40).
 11. The systemaccording to claim 10, wherein the transmitting elements (T2) andreceiving elements (R2) of the filling cap (10) are operativelyconnected to a second microprocessor (110) provided in said filling capand which commands the selective energization of the electromagneticclutch for opening and closing operations of the filling cap (10).